This invention relates to an portable self-contained breathing apparatus and, more particularly, to an auxiliary supply system for providing an alternate source of air for said apparatus.
Portable self-contained apparatus breathing systems are well known in the art and are normally designed for use in hazardous atmospheres such as fires, smoke, and the like or, alternatively, in underwater applications such as scuba diving and deep sea diving. These known devices normally utilize a portable cylinder of pressurized air which is strapped to the user's back and connected, via a hose, to a breathing apparatus associated with a facepiece worn by the user. Upon release of the air from the air cylinder, air is transported into the interior of the facepiece. Normally a demand system is utilized which includes a valve responsive to breathing of the user for controlling the flow of air into the interior of the facepiece.
However, these type arrangements suffer from two major defects. One, they have a finite, somewhat limited, supply of air which limits their use to a relatively short time. Two, in the event of malfunction of any of the basic components of the apparatus, including the air cylinder, the mask, the control valve, and the hoses, the supply of the air to the user is terminated, with potentially disastrous results.